Inorganic nanocrystals may be viewed as an emerging new class of macromolecules. Since methods were developed to encapsulate nanocrystals with a monolayer of protective surfactant (see M. L. Steigerwald, et al., J. Am. Chem. Soc. 110, 3046 (1988); G. Schmid, Chem. Rev. 92, 1709 (1992)), nanocrystals have been assembled as active components inside plastic electronics (see V. Colvin, M. Schlamp, A. P. Alivisatos, Nature 370, 354 (1994); B. O. Dabbousi, M. G. Bawendi, O. Onotsuka, M. F. Rubner, Appl. Phys. Lett. 66, 316 (1998); and W. U. Huynh, X. Peng, A. P. Alivisatos, Adv. Mat. 11, 923 (1999)), and they have been assembled into dimers, trimers (C. J. Loweth, W. B. Caldwell, X. Peng, A. P. Alivisatos, P. G. Schultz, Angew. Chem., Int. Ed. Engl. 38, 1808 (1999)), and crystals of nanocrystals (C. B. Murray, C. R. Kagan, M. G. Bawendi, Science 270, 1335 (1995); C. A. Mirkin, R. L. Letsinger, R. C. Mucic, J. J. Storhoff, Nature 382, 607 (1996)). In each case, the nanocrystals are treated as a conventional polymer or biological macromolecule from the assembly point of view. This enables a wide range of chemical macromolecular assembly techniques to be extended to inorganic solids, which possess a diverse range of optical, electrical, and magnetic properties (A. P. Alivisatos, Science 271, 933 (1996)).
One notable characteristic of some organic macromolecules is their propensity to form liquid crystalline phases when they possess a rod-like shape (J. C. Horton, A. M. Donald, A. Hill, Nature 346, 44 (1990); and T. E. Strzelecka, M. W. Davidson, R. L. Rill, Nature 331, 457 (1988)). While organic liquid crystals are widely used today, there has been a growing interest in inorganic liquid crystals. Existing inorganic liquid crystals include nanoparticles made from gibbsite (Al(OH)3) and boehmite (AlO(OH)) (J.-C. P. Gabriel, P. Davidson, Adv. Mat. 12, 9 (2000); and A. S. Sonin, J. Mat. Chem. 8, 2557 (1998)).
Improvements could be made to the liquid crystal compositions described above. For example, liquid crystal compositions including gibbsite or boehmite nanoparticles have poor optical and electrical properties, and therefore, the potential application of the liquid crystal compositions with gibbsite or boehmite is very limited. It would be desirable to provide for improved inorganic liquid crystal compositions with components with interesting optical, electronic properties so that they can be used in devices. Embodiments of the invention address the above problems, individually and collectively, as well as other problems.